Packaging under air pressure



Feb. 5, 1957 Filed June 25, 1953 B. T. HENSGEN 2,780,043

PACKAGING UNDER AIR PRESSURE s Sheets- Sheet 1 INVENTOR. BER/MPO 7f f/E/VSEf/V Feb. 5, 1957 B. T. HENSGEN 2,730,043

PACKAGING UNDER AIR PRESSURE Filed June 25, 1955 s Sheets-Sheet T2 IN VEN TOR. BfR/VAAW 7. HEA SG'E/V ATTORNEY Feb. 5, 1957 B. 'r. HENSGEN Filed June 25, 1955 PACKAGING UNDER AIR PRESSURE 3 Sheets-Sheet 3 INVENTOR. BER/YARD 7: Hz-wsw/v sydij/y ATTOR/Vf) United States Patent PACKAGING UNDER Am PRESSURE Bernard T. Hensgen, Chicago, 11]., assignor to Swift 85 (Zompany, (Ihicago, Ill, a corporation of Illinois Application June 25, 1953, Serial No. 364,160

4 Claims. (Cl. 53-112) The present invention relates to a method and apparatus for packaging product in deformable evacuated containers.

With many food products it is desirable, particularly from the standpoint of preservation, to have as little air as possible in the container, as the presence of air may accentuate the development of various deleterious effects in the product. It will be apparent to those skilled in the art that similar problems occur with respect to nonedible products as for example various chemicals and the invention is applicable to such other fields.

Two factors which are somewhat interrelated have to be taken into consideration in this problem of removal of air. One of these factors is the reduction in density of the air in the package. The second of the factors is the reduction and/or elimination of voids within the package. These voids may be either between the separate pieces of product in the package in those cases where the product in a package is in more than one piece, or between the product and the Wrapper.

In the past attempts to achieve a reduc ion of air within the package have been concerned with the evacuation of the interior of the package. The present invention is directed to a method and apparatus for applying a superatmospheric pressure to the exterior of the package and at the same time the interior of the package is evacuated so as to achieve the principal object of the invention which is to produce a package of product in which the density of air and the amount of voids is reduced to a practical minimum.

A further object of the invention is to speed the removal of the air from the package.

Generally speaking, vacuumpumps necessary to achieve a relatively high vacuum become quite a large expensive piece of apparatus with a substantial power consumption in their operation. A further object of the invention is to obtain an equivalent or better air reduction in a package as compared to such a vacuum pump with a substantial smaller capital investment and operating expense.

Other objects and advantages will become apparent from the following description taken in conjunction with the drawings in which:

Figure l is a sectional elevation of an embodiment of the invention;

Figure 2 is a schematic wiring diagram for the embodiment of Figure 1;

Figure 3 is a timing diagram illustrating the relationship of the various steps or" the operation of the invention;

Figure 4 is a plan view of a package prepared for evacuation in the embodiment of Figure 1;

Figure 5 is a partial sectional elevation of a second embodiment of the invention; and

Figure 6 is a section taken at line 6-4; of Figure 5.

Referring to the embodiment of Figure l, the device is mounted on a frame, generally 1d, the lower portion of which is in the form of an enclosed cabinet ll. On the top of cabinet 11 is a pressure chamber, generally 12, made up of an upper and lower half 13 and 14-, respectively. Around the edges of the halves 13 and 14 are a pair of resilient rubber gaskets 15 and 16, respectively.

The lower half 14- of the pressure chamber is secured to the top of cabinet 11 while the upper half 13 is attached to a piston rod 18 of an air cylinder 19. The fluid pressure utilized in the operation of the embodiment of Figure l is air which is supplied under pressure by an air pump 20 driven by a motor 21 to a reserve air tank 22. A pipe 23 having a valve 24 therein, which valve is controlled by a solenoid 25, communicates with tank 22 and with the interior of pressure chamber 12 through the bottom half 14 thereof. A pipe 27 having one end open to the atmosphere has the other end connected to a T 28 in pipe 23. Intermediate the ends of pipe 27 is a valve 29 actuated by a solenoid 30. Valve 29 permits pressure chamber 12 to be exhausted to atmosphere during the cycle of operation.

The operation of air cylinder 19 is controlled by a slide valve 32 actuated by a solenoid 33. Valve 32 is connected to the two ends of air cylinder 19 by a pair of pipes 34 and 35 and to reserve tank 22 by a pipe 36. The operation of valve 32 will be readily understood by those skilled in the art. In one position the pressure is applied to one end of cylinder 19 from tank 22, while the other end of the cylinder is exhausted to atmosphere through the valve. When the valve changes position by being actuated by solenoid 33, the air pressure is applied to the other end of cylinder 19 while the first end is exhausted to atmosphere .thuschangin-g the position of the piston (notshown) andpiston rod 18.

At each end of pressure chamber 12 are evacuating needles 38 and 39, respectively. While two needles are used in the disclosed embodiment, it will be apparent that in some embodiments one would be sutficient. The needles are hollow with the ends thereof adjacent the chamber 12 being of very small external configuration and With the rearward ends of the needles of substantially larger configuration. The hollow interior of the needles 38 and 39 communicates with flexible hoses 49 and 41, respectively, which in turn are connected to a branching pipe 42. The other end of pipe 42 is connected to a reserve vacuum tank 43 which is kept at a low pressure by a vacuum pump 44 driven by a motor 45'. The vacuum applied to the needles is controlled by a valve 47 in pipe 42. Valve 47 is actuated by a solenoid 48.

Needles 38 and 39 are secured to the ends of piston rods 59 and 51 of air cylinders 52 and 53, respectively. The two air cylinders 52 and '53 communicate with and are controlled by a slide valve 54 actuated by a solenoid 55. Valve 54 is also connected to reserve tank 22. The actuation of cylinders SZ and 53 by valve 54 corresponds to the operation of cylinder 19 by valve 32, previously described.

The final sealing of the package is done with two pairs of electrodes, i. e., lower electrodes 57 and 58 and corresponding upper electrodes 59 and 60, respectively. Each of the electrodes is mounted in a bearing 61 which holds the electrodes aligned with the portion of the package penetrated by needles 38 and 39 and permits the electrodes to move longitudinally toward and away from the package. The electrodes are each urged into a retracted position, away from the package, by springs 62 compressed betwcen bearings 61 and pins 63 through the electrodes. The upper end of the two upper electrodes 5? and contact a pair of earns 65 fastened to a shaft 66. Similarly the lower end of the two lower electrodes 57 and 58 ride on cams 67 attached to a shaft 68. Each of shafts 66 and 68 are suitably journaled in a plurality of bearings 69 attached to frame 10. A pair of sprockets 70 and 71 are secured to the ends of shafts 65 and 68, respectively, and are connected by a chain '72. Shaft 3 68 is connected through a speed reducer 74 to a motor 75 to drive the two shafts.

Shaft 68 also carries a plurality of timing cams 77 through 82 which actuate switches 84 through 89, respectively.

Referring to the wiring diagram in Figure 2, it will be seen that a transformer 92 connected to a suitable source of electric power is used to provide a low voltage for the control circuits to which the switches 84 through 89 are connected. Switch 84 is connected in series with solenoid 55 of valve 54 controlling the position of the needles 38 and 39. Switch 85 is connected in series with solenoid 33 actuating valve 32 controlling the position of the cover positioning cylinder 19. Switch 86 is connected in series with solenoids 25 and 30 of valves 24 and 29, respectively. As will be seen from the subsequent description, the two valves 24 and 29 are such that energizing the solenoids produces a reverse positioning of the two valves. Switch 87 is similarly connected in series with solenoid 48 of the vacuum valve 47. Switch 88 is connected to the coil 93 of a relay 94 which energizes the high frequency generator 95.

A starting switch 96 is connected in series with a coil 97 of a latching relay 98. The unlatching coil 99 of relay 98 is connected in series with the contacts 89. The motor 75 is energized from a suitable source of power through the normally opened contacts of a relay 101 having a relay coil 102 to close the relay contacts. Coil 102 is connected in series both with the contacts of relay 98 and with the switch contacts 89, the two sets of contacts being in parallel to each other in this particular circuit.

The cycle of operation of the embodiment of Figure 1 is illustrated diagrammatically by Figure 3. Initially all of the switch contacts 84 through 89 are open. The momentary closing of starting switch 96 energizes coil 97 to close the contacts of relay 98 which in turn energizes coil 102. Since this is a latching type relay the contacts remain closed after switch 96 is opened. The energizing of coil 102 closes the contacts of relay 101 to start the motor 75. Prior to the closing of starting switch 96 the package of product to be evacuated and sealed has been placed in chamber 12 which at that time was open.

Switch contacts 84 which control the position of the needles are the first to close because of the rotation of the motor, and they set the postiion of slide valve 54 so that the air pressure is applied to the outer ends of cylinders 52 and 53 to move the two needles inwardly and penetrate the unsealed ends 104 and 105 of the package of product 106. Next contacts 85 close to energize solenoid 33 to apply air pressure to the upper end of cylinder 19 with the lower end thereof being exhausted to atmosphere so that the upper half 13 of chamber 12 comes down in place. The rubber gasket 15 and 16 form a seal both around the periphery of the chamber 12 and across the bulges caused by the insertion of needles 38 and 39.

Switch contacts 86 are the third to close to energize the two coils 25 and 30. Valve 29 is so constructed that the energizing of coil 30 close the valve to cut oif the interior of the chamber 12 from the atmosphere. On the other hand valve 24 opens upon the energizing of the coil 25 to apply superatmospheric air pressure to the interior of chamber 12.

Next vacuum is applied to the needles 38 and 39 from tank 43 by the opening of valve 47. This is accomplished by coil 48 being energized in response to the closing of contacts 87. As will be seen from Figure 3 the situation existing at this point in the cycle of operations is maintained for a substantial portion of the operating cycle. At the end of this portion of the cycle, valve 47 is closed by the deenergizing of coil 48 (contacts 87 having opened) and almost immediately thereafter the needles are Withdrawn by the repositioning of slide valve 54 in response to the deenergizing of solenoid 55 (contacts 84 having opened). Springs (not shown) in the valves reposition the valves when the solenoids are deenergized. With the withdrawing of the needles the gaskets 15 and 16 press the ends 104 and of package 106 tightly together to maintain the low pressure conditions within the package.

At this point in the cycle cams 65 and 67 bring electrodes 57 through 66 into contact with the sides of the ends 104 and 105 of the package 1106. Switch 88 closes to energize coil 93 and close the contacts of relay 94 to apply power to the high frequency generator 95. The process of sealing films by dielectric heating produced by a high frequency generator is well-known in the art and the details of the generator or of how the dielectric sealing is accomplished forms no part of the instant invention.

After the seal has been accomplished the high frequency generator 95 is deenergized and electrodes 57 through 60 are withdrawn from the end of the package by the further rotation of cams 65 and 67 and the pressure of springs 62. It will be apparent that the deenergizing of the high frequency generator 95 is accomplished by the opening of contacts 88 to release the contacts of relay 94.

Subsequently switch 86 is opened repositioning valves 24 and 29. This shuts off the interior of the case from the air supply tank 22 and at the same time opens the interior :of the case to atmosphere through pipe 27. As soon as this is accomplished contacts 35 open to deenergiz solenoid 33 permitting slide valve 32 to reposition itself so that the air pressure from tank 22 is applied to the lower end of cylinder 19 through pipe 35 while the upper end of the cylinder is exhausted to atmosphere through pipe 34.

The cycle is ended by the closing of contact 89 to create a circuit through the unlatching coil 99 of relay 98 and open the contacts of relay 98. At this point relay 101 remains energized through the switch contact 89. However, immediately thereafter switch contact 89 opens to deenergize relay coil 102 and allow the armature of relay 101 to open disconnecting motor 75 from the line. The apparatus is now in condition to repeat the cycle upon the reclosing of the starting switch 96. The case is open which permits the sealed package to be removed and a new package inserted.

While electrodes 57 through 60 may be sufliciently wide to seal the complete width of the package at one time, I prefer to use a partially presealed package as illustrated in Figure 4. As are shown, in this case the preevacuation seals 108 and 109 are made across the ends of the package except for small gaps 110 and 111 which are left for the insertion of needles 38 and 39. Thus the electrodes 57 through 60 need be wide enough only to seal these gaps. An advantage of the presealing is that the film is held in place by the preseals 108 and 109 so that there is little, if any, tendency for the film to wrinkle or shift out of shape as the top 13 of the pressure chamber is lowered into place.

Figures 5 and 6 illustrate an alternative embodiment of the invention. In this embodiment the package 115 in which the product 116 has already been scaled is placed in a pressure chamber 117. The needle 118 is inserted through a double walled portion of the package as seen in Figure 6. A semi-fluid sealing compound 119 is contained in this portion of the package between the two walls 120 and 121. The sealing compound may be any one of a number of substances that are used for a similar purpose in other applications, as for example an unvulcanized or a partially vulcanized rubber compound will be suitable.

The needle 118 is mounted on a rod 123 supported in bearings 124. A lever 125 is connected to rod 123. Lever 125 is secured to a shaft 126 journaled in a wall of chamber 117. Outside of the chamber a handle 127 is also secured to shaft 126.

After the needle 118 has been inserted into the package thejdoor 128 of thechamber is closed and fluid pressure is applied to the interior. of the chamberthrough a pipe 130. Vacuum is applied to the hollow interior of the needle through a pipe 131 having a flexible connection 132 communicating with the hollow interior of needle 118. After the package 115 has been evacuated .and the film forming the walls of the package pressed tightly about the material 116 in the package, the vacuum line 131 and the pressure line130 are shut ed. The needle 118 is withdrawn from the package by turning handle 127 to raise rod 123. The interior of the chamber 117 is brought back toatmospheric pressure and door 123 opened to remove the package 115.

The foregoing description of a specific embodiment is for the purpose of compliance with 35 U. S. C. 112, and I do not desire to be limited to the exact details shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. A device for use in vacuum packaging ofproduct in a flexible wrapping material, said device including a pressure chamber member, a first part of said chamber member being movable away from a second part of said chamber whereby said chamber member may be opened for the insertion of a wrapped and unsealed package of product, with the unsealed portion of the package extending outwardly from said chamber in a predetermined portion of said chamber member, resilient pads about the adjacent edges of said chamber member at said portion thereof whereby when said first part of said chamber member is moved against said second part after the insertion of the unsealed package said pads will apply pressure against the outer surfaces of the un sealed portion of said package to prevent the passage of fluid therethrough, a fluid line communicating with the interior of said chamber member whereby the fluid pressure in said chamber may be adjusted after said chamber is closed, a hollow member having an opening extending to the exterior thereof from the hollow interior thereof adjacent one end thereof, said hollow memher being aligned with the line of juncture of said resilient pads with said one end directed toward said chamber member, a fluid line communicating with the hollow interior of said hollow member, and means to move one of said members with respect to the other of said members whereby said hollow member may be inserted into the unsealed portion of said package with the pads pressing the film about said hollow member to restrict the passage of fluid about the periphery of the hollow member with the fluid in the package being adjusted through the interior of the hollow member and the pads pressing the unsealed portions of the package together to hold the fluid conditions within the package upon the withdrawal of the hollow member.

2. A device for se in vacuum packaging of product in a flexible wrapping material, said device including a pressure chamber member, a first part of said chamber member being movable away from a second part of said chamber whereby said chamber member may be opened for the insertion of a wrapped and unsealed package of product, with the unsealed portion of the package extending outwardly from said chamber member in a predetermined portion of said chamber member, resilient pads about the adjacent edges of said chamber member at said portion thereof whereby when said first part of said chamber member is moved against said second part after the insertion of the unsealed package said pads will apply pressure against the outer surfaces of the unsealed portion of said package to prevent the passage of fluid therethrough, a fluid line communicating with the interior of said chamber member whereby the fluid pressure in said chamber member may be adjusted after said chamber member is closed, a hollow member having an opening extending to the exterior thereof from the hollow interior thereof adjacent one end thereof, said hollow member being aligned with the line of juncture of said resilient pads with said one end directed toward said chamber member, a-fluid line communicating with the hollow interior of said hollow member, means to move one of said members with respect to the other of said members whereby said hollow member may be inserted into the unsealed portion of said package with the pads pressing the film about said hollow member to restrict the passage of fluid about the periphery of the hollow member with the fluid in-the package being adjusted through the interior of 'the hollow member and the pads pressing the unsealed portions of the package together to hold the fluid conditions within the package upon the withdrawal of the hollow i member,.-and means outside said chamber member and adjacent said .portion thereof to permanently seal said unsealed portion after the withdrawal of said hollow member.

3. A device for use in vacuum packaging of product in a flexible wrapping material, said device including a pressure chamber member, a first part of said chamber member being movable away from a second part of said chamber whereby said chamber member may be opened for the insertion of a wrapped and unsealed package of product, with the unsealed portion of the package extending outwardly from said chamber in a predetermined portion of said chamber member, resilient pads about the adjacent edges of said chamber member at said portion thereof whereby when said first part of said chamber member is moved against said second part after the insertion of the unsealed package said pads will apply pressure against the outer surfaces of the unsealed portion of said package to prevent the passage of fluid therethrough, a fluid line communicating with the interior of said chamber member whereby the fluid pressure in said chamber may be adjusted after said chamber is closed, a valve in said fluid line to control the flow of fluid therethrough, a hollow member having an opening extending to the exterior thereof from the hollow interior thereof adjacent one end thereof, said hollow member being aligned with the line of juncture of said resilient pads with said one end directed toward said chamber member, a fluid line communicating with the hollow interior of said hollow members, a valve in said fluid line to control the flow of fluid therethrough, means to move one of said members with respect to the other of said members whereby said hollow member may be inserted into the unsealed portion of said package with the pads pressing the film about said hollow member to restrict the passage of fluid about the periphery of the hollow member with the fluid in the package being adjusted through the interior of the hollow member with the pads pressing the unsealed portions of the package together to hold the fluid conditions within the package upon the withdrawal of the hollow member, and power means connected to said first part of said chamber and to said last mentioned means to open said cham ber whereby an unsealed package may be inserted therein, to close said chamber, to move said one member with respect to said other member to insert the hollow member into the package, and to actuate said valves to adjust the fluid conditions in said chamber and in said package.

4. A device for use in vacuum packaging of product in a flexible wrapping material, said device including a pressure chamber member, a first part of said chamber member being movable away from a second part of said chamber whereby said chamber member may be opened for the insertion of a wrapped and unsealed package of product, with the unsealed portion of the package extending outwardly from said chamber in a predetermined portion of said chamber member, resilient pads about the adjacent edges of said chamber member at said portion thereof whereby when said first part of said chamber member is moved against said second part after the insertion of the unsealed package said pads will apply pressure against the outer surfaces of the unsealed portion of said package to prevent the passage of fluid therethrough,

a fluid line communicating with the interior of said chamber member whereby the fluid pressure in said chamber may be adjusted after said chamber is closed, a valve in said fluid line to control the flow of fluid therethrough, a hollow member having an opening extending to the exterior thereof from the hollow interior thereof adjacent one end thereof, said hollow member being aligned with the line of juncture of said resilient pads with said one end directed toward said chamber member, a fluid line communicating with the hollow interior of said hollow member, a valve in said fluid line to control the flow of fluid therethrough, means to move one of said members with respect to the other of said members whereby said hollow member may be inserted into the unsealed portion of said package with the pads pressing the film about said hollow member to restrict the passage of fluid about the periphery of the hollow member with the fluid in the package being adjusted through the interior of the hollow member with the pads pressing the unsealed portions of the package together to hold the fluid conditions within the package upon the withdrawal of the hollow member, means outside said chamber member and adjacent said portion thereof to permanently seal said unsealed portion after the withdrawal of said hollow member, and power means connected to said first part of said chamber and to said last mentioned means to open said chamber whereby an unsealed package may be inserted therein, to close said chamber, to move said one member with respect to said other member to insert the hollow member into the package, and to actuate said valves to adjust the fluid conditions in said chamber and in said package and withdraw said hollow members and seal the unsealed portions of said package and open said chamber for the removal of said package.

References Cited in the file of this patent UNITED STATES PATENTS 1,003,114 Kirchhoff Sept. 12, 1911 1,885,142 Reece Nov. 1, 1932 1,961,126 Becker June 5, 1934 1,970,193 Riebel Aug. 14, 1934 2,102,716 Berch Dec. 21, 1937 2,241,943 Berch May 13, 1941 2,486,760 Pfeifier Nov. 1, 1949 2,712,208 Campbell July 5, 1955 

